Semiconductor memory devices are classified into volatile semiconductor memory devices and nonvolatile semiconductor memory devices. The read and write speeds of the volatile memory device are fast, but when a power supply is interrupted, data stored therein disappears. In contrast, the data content of a nonvolatile semiconductor memory device does not disappear when the power supply is interrupted. Therefore, the nonvolatile semiconductor memory device retains the data content regardless of whether a power supply is supplied or not.
The nonvolatile semiconductor memory device typically includes a flash memory device. The flash memory device is being used as a voice and image data storage medium of information devices such as a computer, a cellular phone, a smartphone, a personal digital assistant (PDA), a digital camera, a camcorder, a voice recorder, an MP3 player, a handheld PC, a game console, a facsimile, a scanner, and a printer. Technologies for high-capacity, high-speed input/output, and low-power nonvolatile memory devices are being developed to mount the nonvolatile memory device in mobile devices including a smartphone.
Regarding the nonvolatile memory device, a copy-back operation is performed to copy data of any one source area back to a destination area. When an error is detected from data of the source area during the copy-back operation, a method corrects the detected error and writes the error-corrected data in the destination area. However, the copy-back operation accompanying the error correction operation increases the time needed to perform the copy-back operation, thus reducing the access performance.